A modified in vitro stripping method to automate the calculation of geometry of corneocytes imaged with fluorescent microscopy: example of moisturizer treatment.

BACKGROUND/PURPOSE: To develop a modification of the stripping method allowing quick automated processing of corneocyte samples to study human skin conditions. Although the previous scrubbing technique and stripping method can provide sufficient information about human corneocytes, they are either subject to artifacts or involve time-consuming data processing. METHODS AND MATERIALS: In the first stage, an adhesive tape is used to collect corneocytes as in the regular stripping method. Then, a D-squame skin indicator is used to divide the collected corneocytes into a lesser populated sample, in which more individual corneocytes can be observed with the help of fluorescent microscopy after dye staining. The method was applied to study the change of corneocytes after moisturizer (glycerin) treatment. RESULTS: The modified stripping method described allows the automated processing of the geometrical characteristics of corneocytes. Data for several hundreds of corneocytes can easily be collected. The analysis of glycerin treatment demonstrated a high sensitivity for the method. An average increase of the corneocyte area of 5.1% was found after 9 days of treatment (the accuracy of the method was 0.5%). CONCLUSION: The method described is suitable for the automated data processing. It allows for the reliable detection of the expansion of the average area of corneocytes after 9 days of daily glycerin treatment.

Atomic force microscopy study of nano-physiological response of ladybird beetles to photostimuli.

BACKGROUND: Insects are of interest not only as the most numerous and diverse group of animals but also as highly efficient bio-machines varying greatly in size. They are the main human competitors for crop, can transmit various diseases, etc. However, little study of insects with modern nanotechnology tools has been done. METHODOLOGY/PRINCIPAL FINDINGS: Here we applied an atomic force microscopy (AFM) method to study stimulation of ladybird beetles with light. This method allows for measuring of the internal physiological responses of insects by recording surface oscillations in different parts of the insect at sub-nanometer amplitude level and sub-millisecond time. Specifically, we studied the sensitivity of ladybird beetles to light of different wavelengths. We demonstrated previously unknown blindness of ladybird beetles to emerald color (∼500nm) light, while being able to see UV-blue and green light. Furthermore, we showed how one could study the speed of the beetle adaptation to repetitive flashing light and its relaxation back to the initial stage. CONCLUSIONS: The results show the potential of the method in studying insects. We see this research as a part of what might be a new emerging area of "nanophysiology" of insects.